Science Speaks is live-blogging from IDWEEK 2013. Meeting in San Francisco from Oct. 2-6, with the theme “Advancing Science, Improving Care,” the conference features breaking scientific advances and approaches in prevention, diagnosis, treatment, and epidemiology of infectious diseases, including HIV and TB.

SAN FRANCISCO, Calif – The longer the delay in starting antiretroviral treatment for a patient who is co-infected and being treated for tuberculosis, the greater the risk that the patient will die, presenters stressed at an IDWeek 2013 session Wednesday. While conventional view and practice has been to delay HIV treatment initiation until after tuberculosis treatment has started, for fear of jeopardizing treatment response for either disease, drug toxicity, or pill burden for patients who have been newly diagnosed with co-infection, Dr. Diane Havlir said, overwhelming evidence has shown that waiting risks patients’ lives.

With fewer than half of people co-infected with HIV and TB receiving antiretroviral treatment, the global response needs to improve, Havlir said. She cited three studies that have shown that initiating antiretroviral treatment early reduces deaths:

The SAPIT study in Durban, South Africa, randomly enrolled 642 HIV-infected adults with immune cell counts under 500 (a normal immune cell — CD4 — count can range from 500 to 1,500 cells per cubic millimeter of blood), who were also infected with TB, in three arms: antiretroviral treatment initiation during TB therapy at 2 weeks, antiretroviral treatment during TB treatment after induction, and antiretroviral treatment after TB treatment completion. Researchers found that mortality was reduced when antiretroviral treatment was started during TB treatment versus after TB treatment was completed.

The CAMELIA study in Cambodia enrolled participants with immune cell counts under 200, with a median immune cell count of 25, and found that earlier initiation of antiretroviral treatment among co-infected patients reduces death by 34 percent.

The STRIDE study, conducted on four continents, found that early initiation reduced mortality by 19 percent among participants who were enrolled with an immune cell count under 250.

The evidence that starting antiretroviral treatment early is compelling, especially for patients with low immune cell counts, Havlir said. Even a delay of a few weeks matters tremendously, as TB speeds the progression of HIV. This means patients are more susceptible to death from TB or other opportunistic infections the longer ART is delayed.

Havlir said that the possibility of worsening TB symptoms or signs is often cited as an argument for delaying antiretroviral treatment, but that even if patients with TB are more likely to experience sometimes severe inflammatory reactions to antiretroviral treatment, the benefits of early antiretroviral treatment far outweigh the risks. As for delaying antiretroviral treatment initiation for fear of drug toxicity, Havlir said that studies show that toxicity is similar whether antiretroviral treatment is started earlier or later, and that there may be more toxicity as antiretroviral treatment initiation is delayed due to the natural progression of HIV. Havlir also said that research shows that the antiretroviral treatment response is the same whether it’s started early or late, so delaying initiation for fear that it would jeopardize the antiretroviral treatment response is also unfounded.
One exception to the rule that antiretroviral treatment should be initiated early among co-infected patients is when an HIV patient is co-infected with TB meningitis, which is a dreaded complication of TB, that is difficult to diagnose, Havlir said. Trials have shown that delaying antiretroviral treatment for at least 8 weeks into TB treatment reduces the very high mortality associated with this condition in HIV patients, and that there’s no benefit to early antiretroviral treatment in patients infected with TB meningitis.

More needs to be done to apply the evidence that initiating antiretroviral treatment early reduces mortality among those co-infected, Havlir said.

“We have the drugs, we have the clinics. This is something that really is changeable,” she said.

Pregnant women infected with HIV are started on ART immediately, no questions asked, she pointed out. That same urgency needs to be applied to treating HIV-TB co-infected patients, she said. World Health Organization guidelines state that all HIV patients co-infected with TB should be started on ART immediately.

Havlir mentioned the PEPFAR scientific advisory board meeting being held this week in Washington, DC, and said that she’s hopeful that there will be a call at the meeting for PEPFAR to start collecting data regarding timing of antiretroviral initiation for those co-infected.